Expansion unit with initial expansion means



April 20, 1965 F. A. TEEPLE, JR 3,178,990

EXPANSION UNIT WITH INITIAL EXPANSION MEANS Filed Nov. 13. 1961 2 Sheets$h eet 1 April 20, 1965 F. A. TEEPLE, JR 3,173,990

EXPANSION UNIT WITH INITIAL EXPANSION MEANS Filed Nov. 13, 1961 2 Sheets-Sheet 2 FIZANK A.TEEPLE7 \Z.

il m ATTORNEYS United States Patent 0 3,178,990 EXPANSION UNIT WITH INITIAL EXPANSION MEANS Frank A. Teeple, Ila, Huntington, W. Va., assignor to H. K. Porter Company, Inc, Pittsburgh, Pa., a corporation of Delaware Filed Nov. 13, 1961, Ser. No. 151,973 6 Claims. (Cl. 85-76) The invention relates generally to the art of mining, and primarily seeks to provide a novel expansion unit for anchoring the roof suspension bolts by which mine ceiling or root portions are supported.

Roof suspension bolts, or as popularly called, roof bolts, are now widely used. In the use of these bolts, holes are drilled vertically, or sometimes at an angle, upwardly into the mine roof or ceiling, and supporting bolts directed through supporting plates or bars engaged with the roof or ceiling, are inserted in the holes and anchored therein for securely supporting the engaged roof portions and portions adjacent thereto. The anchoring of the bolts is effected by employment of expansion units, inserted into the roof bores and through which the bolts are threaded, means being included which are effective upon threading home of the bolts to expand the units and cause them to firmly grip the wall portions defining the bolt receiving bores. It is a purpose of the present invention to provide a novel form of expansion unit which can be easily and economically manufactured, and which is subject to being inserted into a receiving bore with great facility and capable of very securely anchoring a bolt threaded therethrough.

An object of the present invention is to provide an expansion unit of the character herein described wherein an expander plug having an internally threaded bore is enclosed by arcuate shaped shell wings and presents a wedge shaped projection in camming relation between opposed divergent shell edges, so that upon longitudinal movement of said plug, the shell wings will be forced a art.

A further object of the present invention is to provide an expansion unit of the character stated wherein an internally threaded expander plug is enclosed by a shell assembly comprising a central connecting portion and opposed arcuate shaped exterior wing portions, the shell wing portions being on one side, separated along a straight line and on the other side by divergent shell edges, the expander plug being provided with a wedge shaped extension which slidably engages the divergent shell Wing edges andis presented in carnming relation thereto.

Another object of the present invention is to provide a novel expansion unit of the character stated in which an internally threaded expander plug is enclosed by an expanding shell portion consisting of opposed wing sections separated by a ring-like central portion and connected thereto by narrow connecting straps.

Another object of the present invention is to provide a novel shell for use in the herein described expansion assembly wherein the shell comprises opposed arcuately shaped wing portions centrally connected to each other and separated on one side by straight wing edges and on the other side by divergent wing edges.

Another object of the present invention is to provide an expandable shell for use in an expansion unit of the herein described character in which said shell comprises two opposed and centrally connected wings of arcuate shape, separated on one side by straight wing edges, and on the other side by divergent shell wing edges, the straight wing edges having interlocking portions consisting of an edge extension on one straight edge and a cooperating wing edge depression on the other wing edge.

Another object of the present invention is to provide 3,173,999 Patented Apr. 26, 1965 ice an expander plug for use in the expansion assembly herein described, such expander plug having an upper portion and a downwardly extending leg dependency, and a wedge shaped member projecting from said expander plug and said leg dependency, the terminal portion of the wedge shaped member being bifurcated.

Another object of the present invention is to provide an expandable shell for use in the herein described expansion assembly, wherein said shell comprises opposed arcuately shaped wings being separated on one side by straight edges and on the other side by divergent edges, the divergent edges having oppositely aligned edge extensions disposed to form initial point contacts between an enclosed expander plug and the aforementioned divergent shell edges, and there also being included depressions in said edge extensions adjacent the edge extensions and into which said extensions may be deformed.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a top view of the herein described novel shell and expander plug.

FIGURE 2 is a longitudinal view, partly in section,

showing the expansion assembly inserted in a mine ceil ing bore and showing the initial contact of the wedge proection with the camming edges of the shell as well as the initial bearing point at which the shell and ceiling bore walls are in contact.

FIGURE 3 is a view of the expansion assembly similar to FIGURE 2, the unit being shown in its expanded condition.

FIGURE 4 is the expansion assembly of FIGURE 3, turned 90 degrees, and with the shell in section.

FIGURE 5 is a sectional view taken on the line 55 of FIGURE 3.

FIGURE 6 is a sectional view taken on the line 6-6 on FIGURE 3.

FIGURE 7 is a plan view of the expander shell unit in blanked form.

FIGURE 8 is a side View of the shell unit of FIGURE 7, the unit being shown in dot and dash lines as bent about its central connecting straps and with an arcuate shaping of the opposed shell wings.

FIGURE 9 is an enlarged detail view of the lower portion of expansion assembly and depicts a modification in which the shell edges are so shaped in a novel manner so as to provide the initial low point contact with the expansion wedge projection rather than the bifurcated wedge projection ends shown in FIGURE 2.

FIGURE 10 illustrates the structure of FIGURE 9 after the shell edges have been spread apart by the downward movement of the expander plug, a crowding of the shell edge extensions into the underlying shell edge depressions serving to provide a relatively smooth continuation of the camming surface at the lower portion of the wings.

The expansion assembly generally indicated 1, FIG- URE 2, is shown mounted in FIGURES 26 within a mine ceiling bore 2, in position to securely fasten the anchor plate 3 through a supported bolt 4 and its appurtenant head 5, against the mine ceiling 6. The expansion assembly 1 comprises a shell unit generally designated 7 and an expander plug unit generally designated 8.

The nature of the shell of the expander unit will be understood by reference to FIGURES 7 and 8 in which a shell is shown as formed from a flat metal blank. The shell 7 comprises opposed wing sections centrally connected to a ring-like portion 9, having a cross abutment bar 10 disposed diametrically thereacross, by narrow connecting straps 11. The lower edges of the opposed wing sections, as viewed in FIGURE 7, diverge outwardly from the central portion thereof and each terminates in a longitudinal flat edge. The divergent edges 12 provide camming surfaces. These may be undercut, if desired. The wing edges at the top in FIGURE 7 or opposed from the camming surfaces 12 are generally straight edges, parallel to the center line of the shell blank, and may be provided with an extending edge tab 13 on one wing, and a mating edge indentation or tab receiving recess'14 on the other wing, thus providing interlockable, mating shell edges.

As best shown in FIGURE '8, the flat metal blank of FIGURE 7 is bent about the central ring-like portion 9 and at the same time the wing sections 15 may be arouately shaped about their longitudinal median, as indicated in dot and dash lines, so as to present generally, partcyclindrical shell wings. It will be noted that when the opposed wing edges are then brought together they will be on one side, contacting along a median line and having interlocking edge portions 13, 14, and on the other side, separated along the divergent edge portions 12. It is between the divergent edge portions 12 that the projecting wedge of the expander plug unit soon to be described engages said shell and thereby provides for shell expansion by the downward longitudinal movement of said plug betwen the opposed camming edge portions 12.

The expander plug unit generally designated 8, as best shown by FIGURES 2 through 5, comprises a cylindrical upper portion 16 with a side leg dependency 17, extending downwardly therefrom. The expander plug is probe provided for by opposed edge tabs or abutments 31 and downwardly underlying indentations 32, both respectively formed on and in the divergent camming surfaces 12 of the shell wings 15. Thus initial contact of the opposed camming surface is obtained when the wedge shaped projection between the opposed edge shell surfaces contacts the metal tabs or abutments 31. It should be apparent that in this modification the split, bifurcated or dovetailed wedge projection end is not necessary and the wedge projection may take the form as illustrated in FIGURES 9 and 10, that is, a snubbed or flat wedge end portion which may further be flush with the terminal portion of the side leg dependency.

The purpose of providing the wedge shaped projection with bifurcated ends and that of providing the lower portions of the divergent shell wing edges with a tab exten sion and an underlying indentation is the same. By these provisions, initial point contact between the wedge shaped projection and the divergent shell edges is accomplished at the lower ends of the shell wings. Thus, as will become more apparent hereinafter, upon the initial longitudinal movement of the plug, the divergent shell wing edges will be forced apart first at their lower portions because of the aforementioned initial point contacts so that the lower vided with a wedge shaped projection 18 which is either integrally formed or secured to both the cylindrical portion 16 and its side leg dependency 17. The downwardly extending side edges 1% of the wedge projection 18, form the camming surfaces which operationally contact the divergent shell edges 12, 12 and also may be undercut. The lower end of the wedge projection which may extend beyond the leg dependency is generally provided with bifurcated terminal portions 30 constructed in such a manner as to provide for initial contact of the wedge projection with the opposed camming surfaces of the shell edges 12, 12 at points 40. The cylindrical portion of the expander unit 16 is provided with an inwardly threaded bore 20, adapted to receive the threaded supporting bolt 4, and the emergent surfaces thereof may be provided with chamfers 21. Thus it is apparent that by the use of one wedge element, rather than the two which are utilized in many instances, a substantial cost advantage can be realized since the formation of a second wedge projection and its mating edges is obviated. The present single wedge expander assembly has received notable acceptance especially whenused in mine ceiling bore walls which are harder and more unyielding than those normally encountered, that is, when a great deal of lateral expansion of the shell wings is not demanded. As can further be seen, the provision of interengaging portions on the straight shell wing edges allows for greater insertion stability in the present expander assembly. On occasion, when the assembled unit is being forced into the mine ceiling bore, a surface projection or indentation therein, if of great enough extent, will prematurely hang up and bind one side or wing of the expansion shell while the other remains free to be forced further into the ceiling bore. When this happens, the shell wings will no longer be equally opposed to each other, it readily being apparent that the connecting strap cannot prevent this undesirable condition. By providing the straight wing edges with the herein disclosed interlocks, a further stabilization between the shell wings is obtained and if one wing prematurely binds during insertion the interlocking tab will not only prevent the other wing from being forced upwardly ahead but will further aid in overriding the bind area on the ceiling bore walls.

In the modification, illustrated in FIGURES 9 and 10, the initial contact of the camming surfaces 12, 19 may portion of the shell wings will be forced against the adjacent bore defining wall portions and thereby secure the expansion assembly within the mine ceiling bore prior to the more extensive shell'wing expansion brought about by the complete and simultaneous contact of the opposed plug and wing camming edges 19, 12.

- In the preparation of the instant novel expansion assembly for use, the shell unit is bent about the expander plug in the manner previously described so that the expander plug element is enclosed therein, and the side wedge dependencies lie between the camming surfaces presented by the opposed edges 12, 12 of the shell. Thus it can be seen that when the device is to be put into use the plug is contained within said shell so that the assembly upon rough handling such as is encountered in mining operations, will not separate into its component parts. In use, the supporting bolt 8 is placed through the hole 33 in the ceiling mine support plate 3 and threadably engaged with the internal bore 26 of the cylindrically shaped plug portion, and the expander unit and bolt are inserted in the ceiling bore. Upon tightening of the bolt, its threaded end will contact the abutment bar 10, thus stopping its upward motion, and upon further tightening will force the expander plug longitudinally downward between the opposed camming surfaces of the cylindrical shell thus forcing the shell into secure engagement with the ceiling bore walls. Upon the downward movement of the plug, as shown in FIGURES 2 through 4, the individual forked ends'of the wedge projection first engage the wing edges at the points 41? and force the lower ends of the wings apart and then will be deformed inwardly as shown in FIGURE 3'to allow the wing edges to contact the full length of the wedge camming surfaces such as is illustrated in FIGURES 3 and 4.

The shoulder 22 formed by the joint portion between the wedge projection and its appurtenant leg dependency, along with the undercut that may be present in both cooperating cam surfaces, are thus helpful in preventing the expander unit from slipping out from its position within the opposed shell edges. The wedge plug itself, as it slides downwardly between the opposed camming edges of. the shell, further aids in the secure attachment of the expander unit within the mine ceiling bore walls. In this downward movement, the plug, or particularly its wedge shaped extension, presents itself in a more radially disposed position, therebyacting against the bore wall, and aiding in obtaining a more even pressure pattern of the expansion assembly within the mine ceiling bore.

The further modification as shown in FIGURES 9 and 10 operates as follows. The snubbed or flush nose of the the shell edge tab members 31 as shown in FIGURE 9. The tightening movement of the bolt 8 forces the expander plug downwardly between the camming edges of the shell, thus forcing the wedge projection to engage in first effective expander pressure against the lower wing portions at the shell edge tab members 31. Thereupon, the plug projection member acts to force the lower ends of the wings apart and then crowds or forces the metal comprising the tab extensions 31 into the underlying edge depressions 32 thereby making a relatively smooth camming surface of this area, such as by cold working of the metal, as shown in FIGURE 10.

An over-all attendant result obtained through the use of this novel expander unit is that the metal bolts 4 in the ceiling support plates 3 may be readily removed from their positions after a mine room has been worked. This is extremely important from an economical standpoint and the ability for such hardware to be easily removed is provided for by the following. As is apparent from FIGURE 5, the shell edges 12 and the wedge projection camming surfaces 19 forcibly engage each other. Therefore, it can be seen that the forces exerted upon the plug member through the shell action upon the ceiling bore walls will be distributed in a tangential or peripheral direction across the wedge projection. This eliminates to a great extent, the harmful effect of the radially compressive or crushing forces that are attendant upon so many other devices and thereby assures that the bolt will not become engaged or bound with the cooperating thfeads of the plug member with such force that retrieval of the bolts would be next to impossible.

This feature is also important in the actual use of the novel expansion unit. In actual practice each bolt in a ceiling support structure is normally tightened to a specific torque figure, in hopes of distributing equal loads upon each bolt. However, if a bolt becomes bound with the threads of the plug member, it being obvious that the actual weight which any one bolt and its supported plate may bear is related to the actual force which is applied to the bore wall by the expansion unit, the actual torque applied to the bolt will not be correlated to the pressure applied to the bore walls and a condition popularly known as false torque will be present. One of the prime sources of this false torque is caused by the swagging or collapsing of the tapped bore of the plug, thus causing a binding on the thread of the bolt. This is due to the heavy wedging pressures involved. It is obvious that if each bolt in a mine ceiling is not then capable of sustaining its share of the load, disastrous results may follow, with possible injury to both men and equipment that may be beneath the roof. The above described dangerous condition is eliminated by applicants expander unit having a wedge-shaped extension integrally formed or attached thereto which bears the heavy pressures involved in a tangential direction so as to eliminate binding between the threaded expander plug and its cooperating threaded support bolt.

While preferred forms and part arrangements have been shown in illustrating the invention, it is to be clearly understood that various changes in details and part arrangements may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. An expansion unit comprising an expansible shell, an expander plug and a threaded bolt, said shell comprising a pair of arcuately shaped wings connected to each other at one end thereof and free at the other end thereof, a first edge of one of said wings being disposed adjacent to a first edge of the other of said wings, an edge tab on said one of said wings being disposed within a mating recess in the other of said wings, a second edge of each of said wings being disposed adjacent to each other and providing camming edges converging toward the free other end; said expander plug comprising an upper portion having a threaded bore therethrough, a leg depending from said upper portion, a wedge-shaped member disposed on one side of said plug and projecting outwardly from said upper portion and said leg; said wedgeshaped member being disposed between and spaced from said camming edges of said wings; means contacting between said wedge-shaped member and said shell adjacent to said free other end to cause initial expansion of said shell at said free other end thereof; said means comprising bifurcated terminal portions on said wedge, at least one of said portions being expanded laterally of said wedge, said threaded bolt being adapted to be received in cooperative engagement with said threaded bore whereby said wedge-shaped member may be moved into engagement with said camming edges to expand said expansible shell.

2. An expander plug for use in an expansion unit, said plug comprising an upper portion having a threaded bore therethrough, a leg depending from said upper portion, a wedge-shaped member disposed on one side of said plug and projecting outwardly from said upper portion and said leg, said wedge being provided with a bifurcated terminal portion located on the converging end of said wedge, at least one furcation of said terminal portion being laterally expanded.

3. An expansion unit comprising an expansible shell and an expander plug, said shell comprising camming edge portions converging toward one end of said shell, said expander plug comprising a tapered wedge; said wedge being disposed between and spaced from said camming edge portions; and means cooperating between the wedge and the shell at said one end to cause initial expansion of said expansible shell at said one end thereof, said means comprising bifurcated terminal portions on said wedge, at least one of said portions being expanded laterally of said wedge.

4. An expansion unit comprising an expansible shell and an expander plug, said shell comprising camming edge portions converging toward one end of said shell, said expander plug comprising a tapered wedge; said wedge being disposed between and spaced from said camming edge portions; and means cooperating between the wedge and the shell at said one end to cause initial expansion of said expansible shell at said one end thereof, said means comprising an abutment protruding from at least one of said camming edge portions, and an indentation adjacent to said abutment, said indentation being located between said abutment and said one end.

5. An expansion unit comprising an expansible shell, an expander plug and a threaded bolt, said shell comprising a pair of arcuately shaped wings connected to each other at one end thereof and free at the other end thereof, a first edge of one of said wings being disposed adjacent to a first edge of the other of said wings, an edge tab on said one of said wings being disposed within a mating recess in the other of said wings, a second edge of each of said wings being disposed adjacent to each other and providing camming edges converging toward the free other end; said expander plug comprising an upper portion having a threaded bore therethrough, a leg depending from said upper portion, a wedge-shaped member disposed on one side of said plug and projecting outwardly from said upper portion and said leg; said wedge-shaped member being disposed between and spaced from said camming edges of said wings; means contacting between said wedge-shaped member and said shell adjacent to said free other end to cause initial expansion of said shell at said free other end thereof; said means comprising an abutment protruding from at least one of said camming edges, and an indentation adjacent to said abutment, said indentation being located between said abutment and said other end; said threaded bolt being adapted to be received in cooperative engagement with said threaded bore whereby said wedge-shaped member may be moved into engagement with said camming edges to expand said expansible shell.

6. An expansion unit comprising an eXpa-nsible shell, an expander plug and a threaded bolt, said shell comprising a pair of arcuately shaped wings connected to each other at one end thereof and free at the other end thereof; said wings being connected to each other by a ringlike portion, a cross abutment bar disposed centrally of said ring-like portion, and straps connecting said ringlike portion to said wings; a first edge of one of said wings being disposed adjacent to a first edge of the other of said wings, an edge tab on said one of said wings being disposed within a mating recess in the other of said wings, a second edge of each of said wings being disposed adjacent to each other and providing camming edges converging toward the free other end; said eX- pander plug comprising an upper portion having a threaded bore therethrough, a leg depending from said upper portion, a wedge-shaped member disposed on one side of said plug and projecting outwardly from said upper portion and said leg; said wedge-shaped member being disposed between and spaced from said camming edges of said wings; means contacting between said wedge-shaped member and said shell adjacent to said free other end to cause initial expansion of said shell at said free other end thereof; said threaded bolt being adapted to be received in cooperative engagement with said threaded bore whereby said wedge-shaped member may be moved into engagement with said camming edges to expand said expansible shell.

References Cited by the Examiner UNITED STATES PATENTS 691,921 1/02 Wheeler 85-2.4 1,361,836 12/20 Devlin 5-2.4 1,549,327 8/25 Pleister 852.4 1,557,119 10/25 Tomkinson 852.4 2,075,952 4/37 McIntoch 85-2.4 2,440,038 4/48 Baker 85--2.4 2,878,709 3/59 Horvath 85-24 FOREIGN PATENTS 356,044 9/31 Great Britain.

544,004 7/57 Canada.

EDWARD C. ALLEN, Primary Examiner.

CARL W. TOMLIN, Examiner. 

1. AN EXPANSION UNIT COMPRISING AN EXPANSIBLE SHELL, AN EXPANDER PLUG AND A THREADED BOLT, SAID SHELL COMPRISING A PAIR OF ARCUATELY SHAPED WINGS CONNECTED TO EACH OTHER AT ONE END THEREOF AND FREE AT THE OTHER END THEREOF, A FIRST EDGE OF ONE OF SAID WINGS BEING DISPOSED ADJACENT TO A FIRST EDGE OF THE OTHER OF SAID WINGS, AN EDGE TAB ON SAID ONE OF SAID WINGS BEING DISPOSED WITHIN A MATING RECESS IN THE OTHER OF SAID WINGS, A SECOND EDGE OF EACH OF SAID WINGS BEING DISPOSED ADJACENT TO EACH OTHER AND PROVIDING CAMMING EDGES CONVERGING TOWARD THE FREE OTHER END; SAID EXPANDER PLUG COMPRISING AN UPPER PORTION HAVING A THREADED BORE THERETHROUGH, A LEG DEPENDING FROM AN UPPER PORTION, A WEDGE-SHAPED MEMBER DISPOSED ON ONE SIDE OF SAID PLUG AND PROJECTING OUTWARDLY FROM SAID UPPER PORTION AND SAID LEG; SAID WEDGESHAPED MEMBER BEING DISPOSED BETWEEN AND SPACED FROM SAID CAMMING EDGES OF SAID WINGS; MEANS CONTACTING BETWEEN SAID WEDGE-SHAPED MEMBER AND SAID SHELL ADJACENT TO SAID FREE OTHER END TO CAUSE INITIAL EXPANSION OF SAID SHELL AT SAID FREE OTHER END THEREOF; SAID MEANS COMPRISING BIFURCATED TERMINAL PORTIONS ON SAID WEDGE, AT LEAST ONE OF SAID PORTIONS BEING EXPANDED LATERALLY OF SAID WEDGE, SAID THREADED BOLT BEING ADAPTED TO BE RECEIVED IN COOPERATIVE ENGAGEMENT WITH SAID THREADED BORE WHEREBY SAID WEDGE-SHAPED MEMBER MAY BE MOVED INTO ENGAGEMENT WITH SAID CAMMING EDGES TO EXPAND SAND EXPANSIBLE SHELL. 